1. Technical Field
The present invention relates to refining manual input interpretation on touch surfaces. More particularly, the present invention relates to simplifying zoom gesture interpretations and rotate gesture interpretations that a user performs on a touch surface.
2. Description of the Related Art
Multi-touch interfaces allow computer users to control graphical applications with two or more fingers. Multi-touch interfaces include a touch surface (display screen, table, wall, etc.) that recognize multiple simultaneous touch points. This is in contrast to older touch screens that recognize only a single touch point. In order to detect multiple touch points, multi-touch interfaces may use means such as resistance, capacitance, heat, finger pressure, high capture rate cameras, infrared light, optic capture, tuned electromagnetic induction, ultrasonic receivers, transducer microphones, laser rangefinders, or shadow capture.
Multi-touch interfaces enable specific gestures to be interpreted as particular commands, such as zoom commands and rotate commands. For example, in the case of a rotate command, the user must have either one finger stationary and move the other finger in an arcing motion, or move both fingers in an arcing motion. In the case of a zoom command, the user must perform an inward or outward “pinch” to zoom in or zoom out. These gestures are not easily reproduced without concentrated effort by the user and require gross and fine motor skills that may be challenging for some users, especially those with special needs. In addition, multi-touch rotate and zoom gesture definitions may cause corresponding detection algorithms to misinterpret a user's intended action. For example, a user may perform a quick rotate gesture that the detection algorithms may interpret as a pinch, thereby performing a zoom command on an object instead of a rotate command.